Correlating the elastic properties of metakaolin-based geopolymer with its composition

Yan, Dongming; Chen, Shikun; Zeng, Qiang; Xu, Sheng; Li, Hedong

doi:10.1016/j.matdes.2016.01.107

Cited by 57 publications

(15 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The geopolymer binder had an elasticity modulus of 7.2 GPa at room temperature and 0.3 GPa after exposure to 1200 • C. The modulus of elasticity in the prepared geopolymer binder was consistent with the previously published results (5-7.8 GPa) [58][59][60]. The highest elasticity modulus at laboratory temperature was found in the sample with the corundum content (34.6 GPa), followed by chamotte (29.9 GPa), cordierite (28.9 GPa), and quartz (26.8 GPa).…”

Section: Mechanical Propertiessupporting

confidence: 90%

Effect of Filler Type on the Thermo-Mechanical Properties of Metakaolinite-Based Geopolymer Composites

Kohout

Koutník

2020

Materials

View full text Add to dashboard Cite

Metakaolinite-based geopolymer binder was prepared at room temperature by mixing calcined claystone and potassium alkaline activator. Various granular inorganic fillers were added, amounting to 65 vol % to form geopolymer composites. The effect of four types of fillers (sand quartz, chamotte, cordierite, and corundum) on the thermo-mechanical properties of metakaolinite-based geopolymer composites were investigated. The samples were also examined by an X-ray diffraction method to determine their phase composition. The pore size distributions were determined by a mercury intrusion porosimeter. The XRD revealed the crystallization of new phase (leucite) after thermal exposure at 1000 °C and higher. Geopolymer binders had low mechanical properties (flexural strength 2.5 MPa and compressive strength 45 MPa) and poor thermo-mechanical properties (especially high shrinkage—total shrinkage 9%) compared to geopolymer composites (flexural strength up to 13.8 MPa, compressive strength up to 95 MPa and total shrinkage up to 1%). The addition of fillers reduced the shrinkage of geopolymers and improved their mechanical properties. The results have shown that the compressive strength tested in situ and after exposure to high temperature are in conflict. Geopolymer composites with the addition of chamotte had the best mechanical properties before and after thermal exposure (compressive strength up to 95 MPa). The average pore size diameters increased with the increasing temperature (from 10 nm to approx. 700 nm). The fillers addition decreased the pore volume (from 250 mm3/g to approx. 100 mm3/g).

show abstract

Section: Mechanical Propertiessupporting

confidence: 90%

Effect of Filler Type on the Thermo-Mechanical Properties of Metakaolinite-Based Geopolymer Composites

Kohout

Koutník

2020

Materials

View full text Add to dashboard Cite

show abstract

“…Alkali activated geopolymers have attracted increasing attention in recent years for their potential uses as construction materials and environmentally cementitious binders that would partly replace ordinary Portland cement (OPC) [ 1 , 2 ]. Studies have shown that geopolymers have excellent mechanical properties [ 3 ], such as high early strength and low shrinkage [ 4 , 5 ]. In addition, geopolymers also can be used as construction panels and fire resistant materials [ 6 ] for their characteristic light weight and thermal insulation properties [ 7 , 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

Preparation and Properties of Alkali Activated Metakaolin-Based Geopolymer

et al. 2016

View full text Add to dashboard Cite

The effective activation and utilization of metakaolin as an alkali activated geopolymer precursor and its use in concrete surface protection is of great interest. In this paper, the formula of alkali activated metakaolin-based geopolymers was studied using an orthogonal experimental design. It was found that the optimal geopolymer was prepared with metakaolin, sodium hydroxide, sodium silicate and water, with the molar ratio of SiO2:Al2O3:Na2O:NaOH:H2O being 3.4:1.1:0.5:1.0:11.8. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were adopted to investigate the influence of curing conditions on the mechanical properties and microstructures of the geopolymers. The best curing condition was 60 °C for 168 h, and this alkali activated metakaolin-based geopolymer showed the highest compression strength at 52.26 MPa. In addition, hollow micro-sphere glass beads were mixed with metakaolin particles to improve the thermal insulation properties of the alkali activated metakaolin-based geopolymer. These results suggest that a suitable volume ratio of metakaolin to hollow micro-sphere glass beads in alkali activated metakaolin-based geopolymers was 6:1, which achieved a thermal conductivity of 0.37 W/mK and compressive strength of 50 MPa. By adjusting to a milder curing condition, as-prepared alkali activated metakaolin-based geopolymers could find widespread applications in concrete thermal protection.

show abstract

“…The changes of strength and pore structure were the consequences of physico-chemical interactions among the metakaolin particles and alkaline activator. Because both the Si/Al ratio and the Na/Al ratio were optimally selected according to the literature data [17] and our previous work [19], all the MKG mortars showed high compressive strengths. Our data did not follow the observation that materials with higher capillary pore volumes have lower strengths [45].…”

Section: Roles Of the Materials' Compositionmentioning

confidence: 99%

“…The engineering performances of geopolymer materials are highly dependent on the material composition, synthesizing method, and curing scheme [10,11,[16][17][18][19]. Among these factors, the material composition may play the most important role, because it decisively impacts the material structures, mechanical properties, and durability performances.…”

Section: Introductionmentioning

confidence: 99%

Compositional Dependence of Pore Structure, Strengthand Freezing-Thawing Resistance of Metakaolin-Based Geopolymers

et al. 2020

Self Cite

View full text Add to dashboard Cite

The understanding of the composition dependent properties and freezing-thawing (F-T) resistance of geopolymer materials is vital to their applications in cold regions. In this study, metakaolin-based geopolymer (MKG) mortars were fabricated by controlling the Si/Al ratio and the Na/Al ratio. The pore structure and strength were measured by mercury intrusion porosimetry and compression tests, respectively, which both showed obvious correlations with the material composition. Mass loss, strength loss, visual rate, and microscopic observation were adopted to assess the changes of the material properties and microstructure caused by F-T loads. The results showed that the strength-porosity relationship roughly followed a linear plot. Increases of the Si/Al ratio increased the capillary pore volume, but decreased the gel pore volume and the F-T resistance. Increases of the Na/Al ratio decreased the gel pore, but roughly enhanced the F-T resistance. The MKG mortar at the Na/Al ratio of 1.26 showed the lowest total pore volume and the best F-T resistance. The mechanisms of our experimental observations were that the abundantly distributed air voids connected by the capillary pores facilitated the relaxation of hydraulic pressures induced by the freezing of the pore liquid. The findings of this work help better clarify the compositional dependence of the pore structure, strength, and freezing-thawing resistance of MKG materials and provide fundamental bases for their engineering applications in cold regions.

show abstract

Correlating the elastic properties of metakaolin-based geopolymer with its composition

Cited by 57 publications

References 51 publications

Effect of Filler Type on the Thermo-Mechanical Properties of Metakaolinite-Based Geopolymer Composites

Effect of Filler Type on the Thermo-Mechanical Properties of Metakaolinite-Based Geopolymer Composites

Preparation and Properties of Alkali Activated Metakaolin-Based Geopolymer

Compositional Dependence of Pore Structure, Strengthand Freezing-Thawing Resistance of Metakaolin-Based Geopolymers

Contact Info

Product

Resources

About